Using Vantage Points
Intermapper can block or suppress notifications for devices that are behind or shadowed by another failed device. This helps to avoid receiving dozens (or hundreds) of notifications for devices that do not respond because there is a router or link down between Intermapper and that device.
When one device depends on another, you can use this dependency to suppress the notifications for devices that depend on the failed device.
You do not need to set the dependencies manually between devices on a map. Instead, Intermapper follows the links that are already part of the map.
To enable dependencies, set a Vantage Point. Vantage Point indicates the position from which Intermapper views the network. You usually set the Vantage Point on the actual device where Intermapper is running. After you set the Vantage Point, Intermapper can determine which devices depend on other devices.
Example 1: All devices are up
The following example shows a map with several interconnected routers. The yellow star on the Intermapper icon shows that it is the map's vantage point.
Example 2: One device is down, shows dependent devices
In the following example, Router2 failed. Intermapper sends the normal notifications for Router2, but it suppresses notifications for any device that depends on it. Icons for the dependent devices are dimmed on the map to show they are shadowed by the failure.
Setting a Vantage Point
To set a map's Vantage Point:
- Make the map editable.
- Select the device or network you want to use as the Vantage Point.
-
From the Monitor menu's Set Info submenu, do one of the following:
- Select Set Vantage Point.
or
- Right-click (or Ctrl-click) a device or network and select Set Vantage Point from the context menu's Set Info submenu.
A small star is displayed next to the item.
Moving and Removing a Vantage Point
You can remove a Vantage Point or move it to a new item.
To move a Vantage Point to a new item:
Set the Vantage Point to the new item as described above.
To remove a Vantage Point:
- Select the item to which the Vantage Point is currently assigned.
-
From the Monitor menu's Set Info submenu, do one of the following
The star next to the item is removed and no Vantage Point is set. Notifications are sent for all map items.
How Vantage Points Work
When a device goes down (when no response has been received from it), dependencies determine whether to suppress the notification.
Starting at the Vantage Point, Intermapper follows the links to the device in question. If the only path to that device passes through a device, a link, or an interface that is already down, Intermapper knows that the device is shadowed, dims its icon, and suppresses the notifications.
If there is no failure along the path, or if there is no path at all (functional or not) to the device, Intermapper allows the notification to go through.
Even though a device is shadowed (and its notifications are suppressed), Intermapper continually probes the device to show its status.
One Vantage Point Per Map
You can define only one Vantage Point per map. Even if a map does not show the machine on which the server is running, you can use the Vantage Point to indicate the communication path from the Intermapper server to the devices on the map.
This allows Intermapper to know which devices are inaccessible if a switch or router goes down.
Managing Notifications for Dependent Devices
If a device fails but has not been polled, notifications for dependent devices can still be sent even though the failed device is responsible for the failure. This can result in unnecessary and inaccurate alerts.
If this happens, configure the notifiers for the dependent devices to have a delay that is longer than a single polling cycle of the devices. In this setup, the dependent devices do not send an alert if the device on which they depend goes down. An alert is sent only for the failed device.